It is well known that in the developed nations and even in the developing nations the percentage of individuals having excess weight if not obesity problems is constantly and progressively increasing. This has important consequences both for the health of individuals and for the overall health cost of the various nations, because it has been amply demonstrated that obesity or even being overweight are important associated causes of cardiovascular and metabolic diseases, such as myocardial infarction, stroke, type II diabetes, etc.
The dietetic measures generally proposed by dieticians to combat and/or prevent excess weight mainly consist of low-calorie or low-fat regimes.
Another widely recommended measure for the control of body weight which is even advocated by the mass media (periodicals, television, etc.) is adoption of the famous "Mediterranean diet", based on foods rich in complex carbohydrates such as pasta, rice, bread and the like.
It is, however, a fact that the widespread use of low-calorie diets and the Mediterranean diet has not in fact resulted in any statistically significant change in the percentage of obese or overweight persons; there is instead a progressive increase in this percentage.
A low-calorie diet can in fact have some temporary effect on reducing body weight but this cannot be maintained for a long period, either because it results in general weakening of the body, or because over the long term it is rejected by the individual because of the monotony of the flavours of the food making it up (essentially meat, fish and greens).
The so-called "Mediterranean diet" is in fact only suitable for maintaining the right weight and the right form in individuals who are engaged in vigorous physical activity. Persons who are engaged in essentially sedentary work can on the other hand experience an increase in weight and an accumulation of lipids when they feed themselves on foods based essentially on carbohydrates.